TY - JOUR T1 - THE SYSTEMIC EXPOSURE OF AN <em>N-</em>METHYL-<span class="sc">d</span>-ASPARTATE RECEPTOR ANTAGONIST IS LIMITED IN MICE BY THE P-GLYCOPROTEIN AND BREAST CANCER RESISTANCE PROTEIN EFFLUX TRANSPORTERS JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 722 LP - 726 DO - 10.1124/dmd.32.7.722 VL - 32 IS - 7 AU - Joseph W. Polli AU - Todd M. Baughman AU - Joan E. Humphreys AU - Kelly H. Jordan AU - Angela L. Mote AU - Lindsey O. Webster AU - Robert J. Barnaby AU - Giovanni Vitulli AU - Luigina Bertolotti AU - Kevin D. Read AU - Cosette J. Serabjit-Singh Y1 - 2004/07/01 UR - http://dmd.aspetjournals.org/content/32/7/722.abstract N2 - GV196771 [E-4,6-dichloro-3-(2-oxo-1-phenyl-pyrrolidin-3-glydenemethyl)-1H-indole-2 carboxylic acid] is a potent antagonist of the modulatory glycine site of the N-methyl-d-aspartate receptor. GV196771 has low oral bioavailability (&lt;10%) and plasma clearance (∼2 ml/min/kg) in rats. P-Glycoprotein (Pgp) and breast cancer resistance protein (Bcrp) are ATP-binding cassette (ABC) transporters that limit the oral absorption of drugs and dietary constituents. The objective of this work was to assess the involvement of Pgp and/or Bcrp on the systemic exposure of GV196771 in mice. In vitro, GV196771 was a Bcrp substrate [basolateral-to-apical/apical-to-basolateral (B→A/A→B) ratio = 5.1] with high passive membrane permeability (Papp = 64–170 nm/s); however, GV196771 was not an in vitro Mdr1a substrate (B→A/A→B ratio = 1.9; no effect of GF120918 on efflux ratio). The role of Pgp and Bcrp on the systemic exposure of GV196771 was assessed by pretreatment of wild-type and Pgp-deficient mdr1a/1b-/- mice with a single oral dose of GF120918 (50 mg/kg; a dual Pgp and Bcrp inhibitor) or vehicle (0.5% hydroxypropylmethylcellulose and 1% Tween 80) 2 h before administration of a single oral dose of GV196771 (2 mg/kg). Compared with wild-type animals, the GV196771 area under the plasma concentration-time curve [AUC(0→6 h)] increased 6.2-fold in Pgp-deficient mice, 10.3-fold in GF120918-pretreated wild-type mice, and 16.4-fold in GF120918-pretreated Pgp-deficient mice. Cmax values changed in parallel with the AUC(0→6 h) values; however, tmax remained relatively unchanged. This study supports a role for Pgp and Bcrp in attenuating the systemic exposure of GV196771 in mice and demonstrates that two ABC efflux transporters can have nonredundant roles in attenuating the disposition of a compound. The American Society for Pharmacology and Experimental Therapeutics ER -